Finally have inventory not crashing for most edge cases. This solves many bugs but mostly closes #58.

gui/dnd_loot.cpp

@@ -61,11 +61,13 @@ namespace gui {
       case LOOT_OPEN:
         END(CLOSE);
         break;
-      case LOOT_SELECT:
+      case LOOT_SELECT: {
-        if(commit_move($loot_ui.$gui, $grab_source, data)) {
+          auto drop_id = std::any_cast<guecs::Entity>(data);
+
+          if(move_or_swap($loot_ui, drop_id)) {
             state(DNDState::LOOTING);
           }
-        break;
+        } break;
       case INV_SELECT:
         if(commit_drop($loot_ui.$gui,
               $status_ui.$gui, $grab_source, data))
@@ -92,11 +94,12 @@ namespace gui {
           state(DNDState::LOOTING);
         }
         break;
-      case INV_SELECT:
+      case INV_SELECT: {
-        if(commit_move($status_ui.$gui, $grab_source, data)) {
+          auto drop_id = std::any_cast<guecs::Entity>(data);
+          if(move_or_swap($status_ui, drop_id)) {
             state(DNDState::LOOTING);
           }
-        break;
+        } break;
       default:
          handle_mouse(ev, $status_ui.$gui);
     }
@@ -114,15 +117,10 @@ namespace gui {
         } break;
       case INV_SELECT: {
           auto drop_id = std::any_cast<guecs::Entity>(data);
-
+          if(move_or_swap($status_ui, drop_id)) {
-          if($status_ui.occupied(drop_id)) {
-            $status_ui.swap(*$grab_source, drop_id);
-            END(CLOSE);
-          } else if(commit_move($status_ui.$gui, $grab_source, data)) {
             END(CLOSE);
           }
         } break;
-        break;
       default:
          handle_mouse(ev, $status_ui.$gui);
     }
@@ -252,13 +250,12 @@ namespace gui {
     }
   }
 
-  bool DNDLoot::commit_move(guecs::UI& gui, std::optional<guecs::Entity> source_id, std::any data) {
+  bool DNDLoot::commit_move(guecs::UI& gui, std::optional<guecs::Entity> source_id, guecs::Entity drop_id) {
     dbc::check(source_id != std::nullopt, "source_id must exist");
 
     auto& grab = gui.get<guecs::GrabSource>(*source_id);
     grab.commit();
 
-    auto drop_id = std::any_cast<guecs::Entity>(data);
     auto& drop = gui.get<guecs::DropTarget>(drop_id);
 
     if(drop.commit(grab.world_entity)) {
@@ -307,4 +304,30 @@ namespace gui {
     clear_grab();
     return result;
   }
+
+  /*
+   * If I refactored everything to use a levelmanager module then
+   * this and many other things could go away. Access to $level is
+   * making this too complicated.  Do this for now, but fix bug #59.
+   */
+  bool DNDLoot::move_or_swap(StatusUI& ui, guecs::Entity drop_id) {
+    if(ui.occupied(drop_id)) {
+      ui.swap(*$grab_source, drop_id);
+      clear_grab();
+      return true;
+    } else {
+      return commit_move(ui.$gui, $grab_source, drop_id);
+    }
+  }
+
+  bool DNDLoot::move_or_swap(LootUI& ui, guecs::Entity drop_id) {
+    if(ui.occupied(drop_id)) {
+      ui.swap(*$grab_source, drop_id);
+      clear_grab();
+      return true;
+    } else {
+      return commit_move(ui.$gui, $grab_source, drop_id);
+    }
+  }
+
 }

gui/dnd_loot.hpp

@@ -50,13 +50,16 @@ namespace gui {
           std::optional<guecs::Entity> source_id, std::any data);
 
       bool commit_move(guecs::UI& gui,
-          std::optional<guecs::Entity> source_id, std::any data);
+          std::optional<guecs::Entity> source_id, guecs::Entity drop_id);
 
       bool hold_item(guecs::UI& gui, guecs::Entity gui_id);
       bool throw_on_floor(guecs::UI& gui, bool from_status);
 
       void clear_grab();
 
+      bool move_or_swap(StatusUI& status_ui, guecs::Entity drop_id);
+      bool move_or_swap(LootUI& ui, guecs::Entity drop_id);
+
       sf::Vector2f mouse_position();
   };
 }

gui/loot_ui.cpp

@@ -47,7 +47,6 @@ namespace gui {
     for(int i = 0; i < INV_SLOTS; i++) {
       auto name = fmt::format("item_{}", i);
       auto id = $gui.entity(name);
-      $slot_to_name.insert_or_assign(id, name);
 
       $gui.set<guecs::Rectangle>(id, {THEME.PADDING,
           THEME.TRANSPARENT, THEME.LIGHT_MID });
@@ -69,7 +68,7 @@ namespace gui {
 
     for(size_t i = 0; i < INV_SLOTS; i++) {
       auto id = $gui.entity("item_", int(i));
-      auto& slot_name = $slot_to_name.at(id);
+      auto& slot_name = $gui.name_for(id);
 
       if(contents.has(slot_name)) {
         auto item = contents.get(slot_name);
@@ -97,7 +96,7 @@ namespace gui {
   }
 
   void LootUI::remove_slot(guecs::Entity slot_id) {
-    auto& name = $slot_to_name.at(slot_id);
+    auto& name = $gui.name_for(slot_id);
     fmt::println("LootUI remove slot inv::Model id={} slot={}", $target, name);
     System::remove_from_container(*$level.world, $target, name);
     update();
@@ -106,7 +105,8 @@ namespace gui {
   bool LootUI::place_slot(guecs::Entity id, DinkyECS::Entity world_entity) {
     fmt::println("LootUI target={} placing world entity {} in slot id {}",
         $target, id, world_entity);
-    auto& name = $slot_to_name.at(id);
+    auto& name = $gui.name_for(id);
+
     bool worked = System::place_in_container(*$level.world, $target, name, world_entity);
     if(worked) update();
     return worked;
@@ -136,4 +136,18 @@ namespace gui {
   bool LootUI::mouse(float x, float y, bool hover) {
     return $gui.mouse(x, y, hover);
   }
+
+  bool LootUI::occupied(guecs::Entity slot) {
+    return System::inventory_occupied($level, $target, $gui.name_for(slot));
+  }
+
+  void LootUI::swap(guecs::Entity gui_a, guecs::Entity gui_b) {
+    if(gui_a != gui_b) {
+      auto& a_name = $gui.name_for(gui_a);
+      auto& b_name = $gui.name_for(gui_b);
+      System::inventory_swap($level, $target, a_name, b_name);
+    }
+
+    update();
+  }
 }

gui/loot_ui.hpp

@@ -13,7 +13,6 @@ namespace gui {
       bool active = false;
       guecs::UI $gui;
       GameLevel $level;
-      std::unordered_map<guecs::Entity, std::string> $slot_to_name;
       DinkyECS::Entity $temp_loot;
       DinkyECS::Entity $target;
 
@@ -34,5 +33,7 @@ namespace gui {
       bool place_slot(guecs::Entity gui_id, DinkyECS::Entity world_entity);
       void add_loose_item(DinkyECS::Entity entity);
       bool drop_item(DinkyECS::Entity item_id);
+      bool occupied(guecs::Entity gui_id);
+      void swap(guecs::Entity gui_a, guecs::Entity gui_b);
   };
 }

gui/status_ui.cpp

@@ -29,7 +29,6 @@ namespace gui {
 
     for(auto& [name, cell] : $gui.cells()) {
       auto gui_id = $gui.entity(name);
-      $slot_to_name.insert_or_assign(gui_id, name);
 
       if(name == "character_view") {
         $gui.set<Rectangle>(gui_id, {});
@@ -102,7 +101,7 @@ namespace gui {
   }
 
   bool StatusUI::place_slot(guecs::Entity gui_id, DinkyECS::Entity world_entity) {
-    auto& slot_name = $slot_to_name.at(gui_id);
+    auto& slot_name = $gui.name_for(gui_id);
     auto player = $level.world->get_the<components::Player>();
     auto& inventory = $level.world->get<inventory::Model>(player.entity);
 
@@ -128,8 +127,7 @@ namespace gui {
     // ground or moving from one container or another, so when loot_ui
     // moves to use an ECS id to a container I can have the System
     // do it.
-    dbc::log(fmt::format("removing slot: {}", slot_id));
+    auto& slot_name = $gui.name_for(slot_id);
-    auto& slot_name = $slot_to_name.at(slot_id);
 
     auto player = $level.world->get_the<components::Player>();
     auto& inventory = $level.world->get<inventory::Model>(player.entity);
@@ -143,25 +141,17 @@ namespace gui {
 
   void StatusUI::swap(guecs::Entity gui_a, guecs::Entity gui_b) {
     if(gui_a != gui_b) {
+      auto& a_name = $gui.name_for(gui_a);
+      auto& b_name = $gui.name_for(gui_b);
       auto player = $level.world->get_the<components::Player>();
-      auto& inventory = $level.world->get<inventory::Model>(player.entity);
+      System::inventory_swap($level, player.entity, a_name, b_name);
-
-      auto& a_name = $slot_to_name.at(gui_a);
-      auto& b_name = $slot_to_name.at(gui_b);
-      auto a_ent = inventory.get(a_name);
-      auto b_ent = inventory.get(b_name);
-      inventory.swap(a_ent, b_ent);
     }
 
     update();
   }
 
   bool StatusUI::occupied(guecs::Entity slot) {
-    dbc::check($slot_to_name.contains(slot), "jank ass slot to name thing isn't loaded right you idiot.");
-
     auto player = $level.world->get_the<components::Player>();
-    auto& inventory = $level.world->get<inventory::Model>(player.entity);
+    return System::inventory_occupied($level, player.entity, $gui.name_for(slot));
-    auto& slot_name = $slot_to_name.at(slot);
-    return inventory.has(slot_name);
   }
 }

gui/status_ui.hpp

@@ -12,7 +12,6 @@ namespace gui {
     public:
       guecs::UI $gui;
       GameLevel $level;
-      std::unordered_map<guecs::Entity, std::string> $slot_to_name;
       ritual::UI $ritual_ui;
 
       explicit StatusUI(GameLevel level);

systems.cpp

@@ -562,3 +562,18 @@ Position& System::player_position(GameLevel& level) {
   auto& player = level.world->get_the<components::Player>();
   return level.world->get<components::Position>(player.entity);
 }
+
+void System::inventory_swap(GameLevel &level, Entity container_id, const std::string& a_name, const std::string &b_name) {
+  dbc::check(a_name != b_name, "Attempt to inventory swap the same slot, you should check this and avoid calling me.");
+
+  auto& inventory = level.world->get<inventory::Model>(container_id);
+
+  auto a_ent = inventory.get(a_name);
+  auto b_ent = inventory.get(b_name);
+  inventory.swap(a_ent, b_ent);
+}
+
+bool System::inventory_occupied(GameLevel& level, Entity container_id, const std::string& name) {
+  auto& inventory = level.world->get<inventory::Model>(container_id);
+  return inventory.has(name);
+}

systems.hpp

@@ -37,4 +37,6 @@ namespace System {
   void remove_from_container(World& world, Entity cont_id, const std::string& name);
   void remove_from_world(GameLevel &level, Entity entity);
   Position& player_position(GameLevel& level);
+  void inventory_swap(GameLevel &level, Entity container_id, const std::string& a_name, const std::string &b_name);
+  bool inventory_occupied(GameLevel& level, Entity container_id, const std::string& name);
 }

wraps/lel-guecs.wrap

@@ -1,5 +1,5 @@
 [wrap-git]
-directory=lel-guecs-0.2.0
+directory=lel-guecs-0.3.0
 url=https://git.learnjsthehardway.com/learn-code-the-hard-way/lel-guecs.git
 revision=HEAD
 depth=1